1. Field of the Invention
The present invention relates generally to audio signal processing and, more particularly, to audio path diagnostics.
2. Related Art
The use of patient-worn and implantable medical devices to provide therapy to individuals for various medical conditions has become more widespread as the advantages and benefits such devices provide become more widely appreciated and accepted throughout the population. In particular, devices such as hearing aids, implantable pacemakers, defibrillators, functional electrical stimulation devices such as Cochlear™ prostheses, organ assist or replacement devices, and other medical devices, have been successful in performing life saving and/or lifestyle enhancement functions for a number of individuals.
One category of such medical devices are hearing prostheses which include but are not limited to hearing aids and Cochlear™ implant systems. Hearing aids are externally-worn devices which amplify sound to assist recipients who have degraded or impaired hearing due to, for example, age, injury or chronic ear or mastoid infections. Cochlear™ implant systems provide the benefit of hearing to individuals suffering from severe to profound hearing loss. Hearing loss in such individuals is due to the absence or destruction of the hair cells in the cochlea which transduce acoustic signals into nerve impulses. Cochlear™ implants essentially simulate the cochlear hair cells by directly delivering electrical stimulation to the auditory nerve fibers. This causes the brain to perceive a hearing sensation resembling the natural hearing sensation normally delivered to the auditory nerve.
Hearing prostheses usually involve the recipient having to wear various electronic components. The performance of such components, particularly those associated with the processing of audio sound, collectively and generally referred to as the audio path, can sometimes deteriorate in a very slow, almost undetectable fashion.
For example, hair and skin particles such as dandruff can settle near the port openings leading to the audio pickup devices such as microphones. These obstructing particles can adhere to the device due to the presence of natural body oils or other substances. Eventually accumulation of such particles may cause changes in the sound quality if left unchecked. There may be other reasons for gradual deterioration in the performance of the audio path, including those related to natural wear and tear as well as aging of mechanical and electro-acoustic parts.
This gradual deterioration in performance is particularly problematic when the recipient of the hearing prosthesis is a child or infant. Such recipients are often unable to report changes in hearing prosthesis functionality, particularly if the gradual drop in performance is related to speech intelligibility. This in turn can impact on the child's speech development and their learning and communication abilities.